“Horton” is the only toon of the spring season, but there is otherwise a range of pics, from Lionsgate and the Weinstein Co.’s martial arts fantasy “The Forgotten Kingdom” to Sony’s horror remake “Prom Night.” Some are harder to categorize, such as Universal’s George Clooney-Renee Zellweger starrer “Leatherheads” and Sony’s drama “21.”

Some studios will try to replicate previous successes, such as Warners, which hopes for “10,000 B.C.” to do the same kind of biz that “300” did last year. DreamWorks-Paramount is betting on “The Ruins” to be as successful as “Disturbia” was.

As usual, the studios will be pulling out all the stops with their summer skeds (Variety, Jan. 21-27), but the release calendar through the end of April is filled with pics that, at least on paper, sound good.

The only serious caveat is that the next three months will again see an all-out traffic jam, meaning films will have to fight hard for their share of the moviegoing public.

The majors will be looking to replicate (or even top) the success last year during the same stretch, led by Warner Bros.’ “300,” which grossed $211 million domestically, the highest cume ever for a pic released in March. Also scoring impressive grosses were “Wild Hogs” ($168 million), Ferrell starrer “Blades of Glory” ($118 million) and “Ghost Rider” ($116 million).

Gone are the days when a studio would open a film and the rival studios would back off.

But a bigger battle is looming Feb. 14, which sees the bows of four pics: Paramount’s “Spiderwick,” based on the bestselling children’s book series, Doug Liman’s “Jumper,” Universal/Working Title’s dramedy “Definitely, Maybe” and Disney’s “Step Up 2 the Streets” (the “Step Up” sequel).

Valentine’s Day has always been a prime time for romancers, but “Definitely, Maybe” could face trouble if “Fool’s Gold” holds.

Every studio in Hollywood is looking to find the next kids’ fantasy franchise, with Par banking on the big-budget “Spiderwick,” based the bestselling book series. On Feb. 22, three wide releases will bow, including two laffers, MGM’s teen comedy “Charlie Bartlett” and Lionsgate’s “Witless Protection,” starring Larry the Cable Guy.

The third new film is Sony’s presidential political thriller “Vantage Point,” directed by Pete Travis. Sony is already heavily advertising the film.

“Horton,” voiced by Jim Carrey and Steve Carell, enters the market March 14. It’s the only animated film of the season, and will look to play strongly through Easter and beyond. Fox released both “Ice Age” movies in March to boffo B.O. grosses.

Fox and New Regency try a counterprogramming tactic with horror pic “Shutter,” from Japanese helmer Masayuki Ochiai.

The March 28 frame offers two dramas and two comedies. Robert Luketic-helmed “21” is based on the real-life story of five MIT students who became card counters and swindled Las Vegas casinos out of millions; the other drama is Paramount’s Iraqi war pic “Stop-Loss.” Directed by Kimberly Peirce, “Stop-Loss” was pushed back from 2007 and 2008. The pic will aim to break the streak of other war-themed pics that had trouble at the fall box office.

Two comedies are David Schwimmer-directed “Run, Fatboy, Run” and MGM/Dimension’s spoof “Superhero Movie.”

On April 4, DreamWorks opens horror-thriller “The Ruins.” That’s also the weekend that “Leatherheads” debuts, as well as Martin Scorsese’s Rolling Stones docu “Shine a Light.”

Fox will go after young males that weekend with David Ayer’s Keanu Reeves crime drama “The Night Watchmen,” penned by James Ellroy and Kurt Wimmer and based on a story by Ellroy. Lionsgate also bows “Prom Night.” Plus, there are two more comedies: U bows raunchy R-rated “Forgetting About Sarah Marshall,” and Fox Atomic unveils “The Rocker.”

The final weekend of spring — summer starts May 2 this year, as least to box office watchers — sees two suspense titles, Fox’s “The List” and Picturehouse’s “Amusement.” Also bowing are comedies “Harold and Kumar Escape From Guantanamo” from New Line and U’s “Baby Mama.”